E-mail addresses and password details for 200,000 registered users of Gawker Media websites are now circulating on peer-to-peer networks after a weekend hack attack. The company warned users to change their passwords -- including on other sites, if they use the same passwords elsewhere.

The websites affected include Lifehacker, Gizmodo, Gawker, Jezebel, io9, Jalopnik, Kotaku, Deadspin and Fleshbot. Users are required to register, providing their e-mail address and a password, in order to leave comments on those websites.

A group named "Gnosis" claimed credit for the attack. The compromised information is now available in a 487 MB file, which can be downloaded from peer-to-peer networks using a torrent now indexed on The Pirate Bay. Other information in the file includes something called "gawker_redesign_beta.jpg" as well as Gawker's server kernel versions.

In the torrent release notes, Gnosis said "So, here we are again with a monster release of ownage and data droppage. Previous attacks against the target were mocked, so we came along and raised the bar a little."

The stored passwords were encrypted although Gnosis said some of the passwords have already been cracked.

Those who linked their Twitter accounts with Gawker do not have to worry about those passwords, Gawker said, while those who logged into Gawker sites using Facebook Connect are safe as Gawker does not store those passwords.

Gawker is recommending that anyone who has a registered account change their password. If someone uses that the same password across other sites, those passwords should be changed as well, Gawker recommended.

"We are in the process of notifying those users who associated an e-mail address with their Gawker accounts," the company said, adding that it will create a feature by which users can delete their account entirely.

Early on Monday, the head of Twitter's Trust and Safety team wrote that a spam attack appeared to be under way on its service. The spam advertises acai berries, a kind of diet aid.

"Got a Gawker acct that shares a PW w/your Twitter acct?," said Del Harvey in a Twitter message. "Change your Twitter PW. A current attack appears to be due to the Gawker compromise."